1. Field of the Invention
The present invention relates to a rubber crawler comprising an endless rubber-crawler belt which extends over a sprocket and an idler tumbler of a vehicle and has a running surface formed on its inner circmference and on which rollers between the sprocket and idler tumbler roll, and also relates to a crawler belt in which many cores are embedded at the base thereof perpendicularly to the longitudinal direction of the crawler belt.
2. Description of the Prior Art
Conventionally, the vehicle of this type which uses a rubber crawler includes a sprocket 1, an idler tumbler 2, an endless rubber-crawler belt 100 which extends over the sprocket 1 and the idler tumbler 2, and a plurality of rollers 3 disposed interiorly of and in contact with the crawler belt 100 between the sprocket 1 and the idler tumbler 2 and which roll along the internal periphery of the crawler belt 100, as illustrated in FIG. 1.
Also as shown in FIG. 2, many cores 101 have the bases thereof embedded in the crawler belt 100 perpendicularly to the longitudinal direction of the crawler belt 100, and have guide projections 102 formed integrally thereon which protrude inwardly to form the inner circumference of crawler belt 100. Further, a tensile reinforcing member 103 such as steel cord or the like is embedded in the crawler belt 100 in such a manner as to surround the outer circumferences of the cores 101. Wheels 3A of which respective pairs compose each roller 3 roll on the inner circumference portions of the crawler belt 100 that are outside the guide projections 102. Sprocket holes 104 for allowing the teeth of the sprocket 1 to be fitted therein are made in the crawler belt 100 between the cores 101, as illustrated in FIG. 3.
Such prior vehicles however suffer from the following problems.
The wheels 3A of the rollers 3, which roll along the internal periphery of the crawler belt 100 alternately on the cores 101 and on a rubber surface between the cores 101 are often subjected to severe vertical motion since the rollers 3 fall onto the rubber surface when reaching that surface.
Additionally, on the internal surface of the crawler belt, 100 along which the rollers 3 are rolled the rubber tends to be stripped from the core 101 at the boundary between the rubber and the core 100 thereby to permit water and sand etc., to enter into the interior of the crawler belt from that boundary to increase the failure of the rubber. Moreover, when each core 101 is covered with only a thin sheet of rubber, that portion is damaged to thereby permit water and mud etc., to enter into that damaged portion 200 as illustrated in FIG. 4. In particular, in the so-called outer roller system, where the wheels 3A, respective pairs of which compose each roller 3, roll along the outside of the guide projections 102, the rubber located outside the projections 102 tends to be damaged. This can be prevented by making the rubber of the crawler belt 100 thicker, but that is not actually done.